what happened in dallas? the assassination of john f. kennedy, sunday at 7:30 p.m. eastern and pacific. >> democratic and republican congressional leaders are voicing optimism about avoiding tax increases and automatic spending cuts in january, the so-called fiscal cliff. leaders from both the house and senate met with president obama this morning at the white house, their first discussion in negotiation on the fiscal cliff. the president started the day with comments to reporters. >> i want to welcome the congressional leadership here and thank them for their time. i think we're all aware that we have some urgent business to do and we got to make sure that taxes don't go up on middle class families, that our economy will remain strong, that we're creating jobs and that is an agenda that democrats and republicans and independents, people all across the country share. so our challenge is to make sure that we are able to cooperate together, work together, find some common ground, make some tough compromises, build some consensus to do the